Juvenile hormones (JHs) of insects are sesquiterpenoids that regulate a great diversity of processes in development and reproduction. As yet the molecular modes of action of JH are poorly understood. TheMethoprene-tolerant (Met) gene of Drosophila melanogasterhas been found to be responsible for resistance to a JH analogue (JHA) insecticide, methoprene. Previous studies onMethave implicated its involvement in JH signaling, although direct evidence is lacking.